mail-crypt key sharing

Hi all,

I am trying to setup mailbox sharing (not public mailboxes) together with mail-crypt plugin and encrypted folder keys.

According to the source code of the mail-crypt plugin (there's code trying to retrieve private keys for shared mailboxes), and its documentation, this should be possible:

If you are using global keys, mails can be shared within the key scope. The global key can be provided with several different scopes:

Global scope: key is configured in dovecot.conf file

Per-user(group) scope: key is configured in userdb file

With folder keys, key sharing can be done to single user, or multiple users. When key is shared to single user, and the user has public key available, the folder key is encrypted to recipient’s public key.

If you have mail_crypt_acl_require_secure_key_sharing enabled, you can’t share the key to groups or someone with no public key.

The documentation mentions key sharing, but I have no idea how this could be implemented, and did not find anything else than this mail- crypt documentation in the whole web...

I assume that I need to export the user key of the users's folder that should be shared, and import it into the receiving users keys, encrypted with the receiving user's key.

Is that right? Any hints how to do that?

Regards,

Robert

-- Robert Senger